Plastic nut or grommet

ABSTRACT

A plastic nut or grommet is provided, of the type which is insertable in an opening in a supporting structure, for the purpose of securing various articles, such as a panel, to the wall structure, or for use as a drawer glide or shelf support. The nut or grommet is of a construction such that a relatively high torque is required on a screw used in conjunction with the nut to secure the nut in the opening, thereby assuring that the nut is firmly and rigidly secured in the opening. Retaining lugs are provided on the nut, which are disposed on relatively thin and flexible portions of the nut, whereby these lugs can flex inwardly, thereby facilitating entry of the shank of the nut in the opening of the support structure.

Elttitefi States Patent 1 Schuplin Sept. 4, 1973 PLASTIC NUT OR GROMMET[75] Inventor: Jerome T. Schuplin, Parma Heights,

[52] US. Cl. 85/80, 85/83 [51] int. Cl. F161) 13/04 [58] Field 0? Search85/80, 82, 83, 84, 85/72; 151/41.75; 24/73 PF, 73 HS, 73 P, 73 PM [56]References Cited UNITED STATES PATENTS 2,836,214 5/1958 Rapata 85/802,836,215 5/1958 Rapata 85/80 3,105,407 10/1963 Rapata 85/72 3,203,3048/1965 Rapata.. 85/84 3,313,083 4/1967 Flora 24/73 PF 3,342,098 9/1967Schuplin 85/83 3,358,551 12/1967 Seckerson 24/73 PF 3,593,612 7/1971Schulze 85/80 FOREIGN PATENTS OR APPLICATIONS 202,089 6/1956 Australia85/82 888,450 l/l962 Great Britain 24/73 HS Primary Examiner-MarionParsons, Jr. Attorney-Isler and Ornstein 5 7 ABSTRACT A plastic nut orgrommet is provided, of the type which is insertable in an opening in asupporting structure, for the purpose of securing various articles, suchas a panel, to the wall structure, or for use as a drawer glide or shelfsupport. The nut or grommet is of a construction such that a relativelyhigh torque is required on a screw used in conjunction with the nut tosecure the nut in the opening, thereby assuring that the nut is firmlyand rigidly secured in the opening. Retaining lugs are provided on thenut, which are disposed on relatively thin and flexible portions of thenut, whereby these lugs can flex inwardly, thereby facilitating entry ofthe shank of the nut in the opening of the support structure.

5 Claims, 13 Drawing Figures Patented Sept. 4, 1973 2 Sheets-Sheet 1Fig. 6

INVENTOR. JEROME T. SCHUPLIN li m ATTORNEYS Patented Sept. 4, 19733,756,116

2 Sheets-Sheet $3 Fig.

INVENTOR. JEROME-T. SCHUPLIN ATTORNEYS FLASTIC NUT OR GROMMET Thisinvention relates generally to plastic fasteners of the nut or grommettype.

Plastic nuts, grommets or fasteners of the type to which this inventionrelates are disclosed in Rapata US. Pat. Nos. 2,788,047 and 2,836,214,and in my U.S. Pat. No. 3,342,098.

Fasteners such as disclosed in the aforesaid Rapata patents arecharacterized by the fact that the shank portions are separated by slotswhich extend from the axial bore of the shank to the sides of the shank,and the shank portions are provided with inclined surfaces which act toretain the shank in a panel or wall opening until the screw which isused in conjunction with the fastener to cause spreading of the shankportions is threaded into the axial bore. Since the shank portions areeasily spread apart by the screw, very little torque on the screw isrequired to cause such spreading, with the result that the nut is notalways held securely in the panel or wall opening into which the shankextends.

On the other hand, in fasteners such as disclosed in my aforesaidpatent, the shank portions are interconnected by a relativelythin-walled tube or membrane, which, due to the fact that its sides areof angular conformation, offers little or no resistance to the spreadingapart of the shank portions by the screw, so that there, again, verylittle torque on the screw is required to cause such spreading, with theresult that the nut is not always held securely in the panel or wallopening into which the shank extends. Moreover, the tapered ribs in thatpatent, which are utilized to retain the shank in the panel or wallopening until the screw is inserted into the nut, are disposed on therelatively thick shank portions of the nut, which are not easily flexedtoward each other, so that it is somewhat difficult to push these ribsinto the panel or wall opening.

The present invention has, as its primary object, the provision of aplastic nut or rivet of the character described, in which the shank ofthe nut or rivet is of such a construction that a relatively high torqueon the screw is required to cause spreading of the shank portions,thereby assuring that the nut will be firmly and rigidly secured in thepanel or wall opening, and, at the same time, the retaining lugs or ribswhich are utilized to retain the shank in the panel or wall openinguntil the screw is inserted into the nut, are disposed on portions ofthe shank which are relatively thin and flexible, so that these lugs orribs can flex inwardly, thereby facilitating entry of the shank into thepanel or wall openmg.

Another object of the invention is to provide a plastic nut of thecharacter described, in which the relatively thick portions of the shankwhich act to retain the nut in the panel or wall opening are devoid ofthe inclined surfaces and lugs or ribs, to which reference has beenmade, thereby simplifying the molding of the nut and the overall designof the nut.

Other objects and advantages of my invention will be apparent during thecourse of the following description.

In the accompanying drawings forming a part of this specification, andin which like numerals are employed to desig-nate like parts throughoutthe same,

FIG. 1 is a top plan view of a preferred form of plastic nut, embodyingthe invention;

FIG. 2 is a side elvational view of the nut, as viewed from the leftside of FIG. 1;

FIG. 3 is a side elevational view of the nut, as viewed from the bottomof FIG. 1;

FIG. 4 is a cross-sectional view of the nut, taken on the line 4-4 ofFIG. 1;

FIG. 5 is a cross-sectional view of the nut, taken on the line 55 ofFIG. 1;

FIG. 6 is a cross-sectional view of the nut, taken on the line 6-6 ofFIG. 3;

FIG. 7 is a fragmentary vertical cross-sectional view, showing the nutof FIGS. 1-6 assembled in a support structure, with a screw insertedthrough the nut for securing an article, such as a panel, to the supportstructure;

FIG. 8 is a perspective view of a modification of the plastic nut orfastener;

FIG. 9 is a perspective view of another modification of the nut;

FIG. 10 is a perspective view of another modification of the nut;

FIG. 1 l is a perspective view of another modification of the nut;

FIG. 12 is a bottom plan view of another modification of the nut, and

FIG. 13 is a bottom plan view of still another modification of the nut.

Referring more particularly to FIGS. 1 to 7 inclusive, the fastener ispreferably of a unitary, one-piece construction made from a polymericmaterial, such as nylon or the like, which may be easily produced inquantity or mass production by conventional extrusion, molding or othersimilar forming methods, as well known in this art.

The device comprises a rectangular or square head 1, and a shank 2, ofsubstantially square external crosssection, the sides of the shank beingdesignated by reference numerals 3, 4, S and 6, it being noted that thisexternal cross-section does not vary in dimensions from the head 1 tothe end of the shank, except at the extreme end of the shank where thesides are curved inwardly slightly to facilitate entry of the shank intoa hole in a support structure.

Extending axially through the fastener is a bore or passageway having abeveled entrant opening 7 in the head I, a short portion 8 of uniformdiameter, which extends partially into'the shank, and a conical portion9, which extends from the portion 8 to the end of the shank.

The shank is provided with cavities or hollow spaces, designated byreference numerals I0 and 11, which extend laterally from points atdiametrically opposite sides of the portion 9 of the bore andlongitudinally from a point 12, adjacent the lower end of the portion 8of the bore, to the end of the shank.

The cavity 10 is of substantially triangular crosssection, defined byconverging walls 13 and 14, and a wall 15, which is substantiallyparallel with the side 3 of the shank 2.

The cavity 11 is likewise of substantially triangular cross-section,defined by converging walls 16 and 17, and a wall 18 which issubstantially parallel with the side 5 of the shank 2.

It may be noted, at this point, that the portions of the shank betweenthe wall 15 and side 3, and between the wall 18 and side 5, arerelatively thin, and are therefore easily flexed inwardly.

At the same time, the portions of the shank between the conical portion9 of the bore and the sides 4 and 6 of the shank are solid and ofsubstantial thickness, so that these portions are not inwardly flexibleto any substantial degree, as compared with the other portions of theshank.

The sides 3 and 5 of the shank are provided with retaining lugs 19 and20, having tapered portions 19a and 20a respectively, these lugs servinga purpose to be presently described.

One manner or mode in which the fastener is used is best depicted inFIG. 7, wherein reference numeral 21 designates a support structure orwall having a square opening 22 which is slightly larger in dimensionsthan the external cross-section of the shank 2 of the fastener.

The shank of the fastener is inserted through the opening 22, thisinsertion being facilitated by the engagement of the tapered portion 19aand 20a of the lugs 19 and 20 with edges of the opening 22, and byreason of the fact that the portions of the shank on which the lugs aredisposed are relatively thin and are thus easily flexed inwardly towardthe bore of the fastener, as the lugs pass through the opening 22.

The function of the lugs 19 and 20 is to prevent the fastener from beingretracted from the opening 22, pending permanent securement of thefastener in the opening.

This permanent securement is effected in the following manner.

After the fastener is in the position shown in FIG. 7, a panel P, whichis to be secured to the wall or support structure 21, is placed adjacentthe head 1 of the fastener, with the hole 23 of the panel in axialalignment with the bore of the fastener.

A screw 24, such as a Phillips head screw, is then inserted into thehole 23 and is then secured to the fastener in the manner shown in FIG.7.

In the course of this securement, the threaded shank of the screw willcut threads in the wall of the portions 8 and 9 of the bore of thefastener, and due to the conical shape of the portion 9 of the bore,will cause the portions of the shank between the portion 9 of the boreand the sides 4 and 6 of the shank to spread apart, thereby forcing thesides 4 and 6 to firmly engage edges of the opening 22 in the wall orsupport structure 21.

Since the portions of the shank of the nut, between the portion 9 of thebore and the sides 4 and 6 of the shank are relatively thick, this,combined with the fact that the portions of the shank on which theretaining lugs are disposed offer substantial resistance to spreadingapart of the thick portions, requires that a relatively high torque beapplied in securing the screw 24 in position, with the result that thenut is rigidly and securely held in the opening 22.

Moreover, since the retaining lugs are not on the thick portions of thenut, as are the ribs in my aforesaid patent, these lugs do not presentan additional factor opposing the entry of the shank of the nut into theopening 22, and the overall construction of the nut is greatlysimplified.

The head of the nut or grommet may be round or polygonal, instead ofsquare, and may vary in thickness in accordance with the requiredspacing between the panels 21 and P. In practice, this variation willusually be from one thirty-second inch to one-half inch.

In FIG. 8, a modification of the nut is illustrated, in which the head31 of the nut is provided with a curved portion 32 of hook-shapedconformation, whereby the nut may be utilized for securing electricalwires or cables, rods, etc., to the support structure in which the nutis mounted. The head 31 may, if desired, be provided with such curvedportions at opposite sides of the head.

In FIG. 9, a modification of the nut is shown, in which the head 41 ofthe nut is provided with a flange 42, whereby the nut may be secured toa support structure, and utilized as a drawer glide or shelf support.

In FIG. 10, a modification is shown, in which the shank of the nut isprovided adjacent the lower end of the bore with a tube-like extension43, which is adapted to receive the end of the screw 24, to whichreference has previously been made, so that the nut may be used inelectrical applications, and the tube-like extension serves to insulatethe exposed end of the screw.

In FIG. 11, a modification is shown, in which the shank of the nut isprovided at opposite sides with retaining lugs or ribs 44 of somewhatdifferent design than the lugs 19 and 20.

In FIG. 12, a modification is shown, in which the shank 45 of the nut isprovided with a conical bore, such as the bore 9 described in connectionwith FIGS. 1 to 7 inclusive, but instead of the cavities 10 and 11 ofthat form of the invention, cavities or slots 46, 47, 48 and 49, spacedcircumferentially of the bore, are provided, which extend radially fromthe bore to points adjacent the corners of the shank.

In FIG. 13, a modification is illustrated, in which the shank 50 of thenut is provided with a conical bore, such as the bore 9 described inconnection with FIGS. 1 to 7 inclusive, but instead of the cavities 10and 11 of that form of the invention, cavities or slots 51 and 52, ofrectangular cross-section, extend from diametrically opposite sides ofthe bore to points closely adjacent the walls 53 and 54 of the shank.

It is to be understood that the forms of my invention, herewith shownand described, are to be taken as preferred examples of the same, andthat various changes may be made in the shape, size and arrangement ofparts thereof, without departing from the spirit of the invention or thescope of the subjoined claims.

Having thus described my invention, I claim:

1. In a combination plastic fastener including nut and grommet portionsfor fastening in an aperture in a panel structure, the combinationcomprising, a fastener body including a head portion, a shank portionand means defining a bore extending therethrough, said head includingpanel engaging shoulder means dimensioned to preclude passage of saidfastener through said aperture, said shank extending from said headportion and defined by a substantially square cross section of adimension smaller than said head and complementary to said aperture,said shank further including a first pair of oppositely disposed wallseach including angularly inwardly directed converging portionsterminating in an arcuate conical wall, each such wall defining aportion of said bore, said shank including a second pair of oppositelydisposed walls interconnecting said first pair, said second pairdimensioned to provide a relatively thin, imperforate, flexible webextending between the angular extremity of said walls of said first pairto define therewith a substantially triangular cavity extending from apoint adjacent said head to the free end of said shank, said boredefined by an entrant opening in said head, a barrel portion of uniformdiameter extending through said head and an interrupted said head isprovided at one side with a flange substantially perpendicular to saidhead.

4. A nut or grommet, as defined in claim 1, wherein said shank isprovided at its outer end, adjacent said bore, with a tube-likeextension formed integrally with said shank.

5. A nut or grommet, as defined in claim 1, wherein said retaining lugshave oppositely sloping faces.

* k i l

1. In a combination plastic fastener including nut and grommet portionsfor fastening in an aperture in a panel structure, the combinationcomprising, a fastener body including a head portion, a shank portionand means defining a bore extending therethrough, said head includingpanel engaging shoulder means dimensioned to preclude passage of saidfastener through said aperture, said shank extending from said headportion and defined by a substantially square cross section of adimension smaller than said head and complementary to said aperture,said shank further including a first pair of oppositely disposed wallseach including angularly inwardly directed converging portionsterminating in an arcuate conical wall, each such wall defining aportion of said bore, said shank including a second pair of oppositelydisposed walls interconnecting said first pair, said second pairdimensioned to provide a relatively thin, imperforate, flexible webextending between the angular extremity of said walls of said first pairto define therewith a substantially triangular cavity extending from apoint adjacent said head to the free end of said shank, said boredefined by an entrant opening in said head, a barrel portion of uniformdiameter extending through said head and an interrupted conical portiondefined by said arcuate conical wall of said first pair, and lug meanscarried by the outer surface of said second pair of shank wallsengageable with the sides of said aperture in said panel to precludeunintended retraction of said shank through said aperture.
 2. A nut orgrommet, as defined in claim 1, wherein said head is provided at atleast one side with a curved extension or hook-like conformation.
 3. Anut or grommet, as defined in claim 1, wherein said head is provided atone side with a flange substantially perpendicular to said head.
 4. Anut or grommet, as defined in claim 1, wherein said shank is provided atits outer end, adjacent said bore, with a tube-like extension formedintegrally with said shank.
 5. A nut or grommet, as defined in claim 1,wherein said retaining lugs have oppositely sloping faces.